From 11da511c784eca003deb90c23570f0873954e0de Mon Sep 17 00:00:00 2001 From: Duncan Wilkie Date: Sat, 18 Nov 2023 06:11:09 -0600 Subject: Initial commit. --- gmp-6.3.0/mpf/set_prc.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 gmp-6.3.0/mpf/set_prc.c (limited to 'gmp-6.3.0/mpf/set_prc.c') diff --git a/gmp-6.3.0/mpf/set_prc.c b/gmp-6.3.0/mpf/set_prc.c new file mode 100644 index 0000000..40c3f0e --- /dev/null +++ b/gmp-6.3.0/mpf/set_prc.c @@ -0,0 +1,68 @@ +/* mpf_set_prec(x) -- Change the precision of x. + +Copyright 1993-1995, 2000, 2001 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +The GNU MP Library is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received copies of the GNU General Public License and the +GNU Lesser General Public License along with the GNU MP Library. If not, +see https://www.gnu.org/licenses/. */ + +#include "gmp-impl.h" + + +/* A full new_prec+1 limbs are always retained, even though just new_prec + would satisfy the requested precision. If size==new_prec+1 then + certainly new_prec+1 should be kept since no copying is needed in that + case. If just new_prec was kept for size>new_prec+1 it'd be a bit + inconsistent. */ + +void +mpf_set_prec (mpf_ptr x, mp_bitcnt_t new_prec_in_bits) +{ + mp_size_t old_prec, new_prec, new_prec_plus1; + mp_size_t size, sign; + mp_ptr xp; + + new_prec = __GMPF_BITS_TO_PREC (new_prec_in_bits); + old_prec = PREC(x); + + /* do nothing if already the right precision */ + if (new_prec == old_prec) + return; + + PREC(x) = new_prec; + new_prec_plus1 = new_prec + 1; + + /* retain most significant limbs */ + sign = SIZ(x); + size = ABS (sign); + xp = PTR(x); + if (size > new_prec_plus1) + { + SIZ(x) = (sign >= 0 ? new_prec_plus1 : -new_prec_plus1); + MPN_COPY_INCR (xp, xp + size - new_prec_plus1, new_prec_plus1); + } + + PTR(x) = __GMP_REALLOCATE_FUNC_LIMBS (xp, old_prec+1, new_prec_plus1); +} -- cgit v1.2.3